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Author: Subject: Taking guesses on BHP
hicost

posted on 6/8/10 at 09:21 PM Reply With Quote
Yes

I can understand that, because I bet you dont take it much past 5500 on normal use, and looking at the graph its gone flat at 4000 onwards.

Needs a good tune really. So difficult with rolling roads though, do you have a AFR gauge in the car, if so I would give it a go myself on the runway till you feel its improved. Just watch it does not go lean.





"I cant do that without accidentally grabbing hold of the work of the divine potter"


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flak monkey

posted on 7/8/10 at 07:24 AM Reply With Quote
12.5 AFR is where peak power will be anyway. It may have gone richer or leaner than that to give the dip in the power curve.

Without the AFR plot alongside the power and torque curves its difficult to comment on what could cause it to drop off at 4000rpm





Sera

http://www.motosera.com

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scutter

posted on 7/8/10 at 10:05 AM Reply With Quote
My intial thoughts are that the VVT isn't being modulted as it is in the ST, so the angle changes from 85 to 145 degrees after TDC in one hit.

Just more time mapping around that point i feel.

I'm going to lower the shift point myself to 3250 and see if it feels better.

ATB Dan.





The less I worked, the more i liked it.

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GeoffT

posted on 7/8/10 at 10:43 AM Reply With Quote
Hi Dan,

Like yourself I was unable to get a progressive control of vvc with ms and had to operate it in a switched mode. I was concerned that changing directly from 0% to 100% vvc might give me a hole in the middle of the curve, fortunately with the 'k' it was fairly easy to fit some 'stops' (actually just spacing washers) in the hydraulic actuator to limit the range to roughly 25% - 75%. This seems to have worked pretty well and has given me a reasonably even curve with little hole in the mid range. I've no idea how the Ford vvt is actuated and whether this 'limiting' is possible, but may be worth looking into.

When I had mine on a rolling road I got them to do a power run with the vvc locked off, and another with it locked on. This helps with a couple of things :-

a) you should be seeing two very different graph shapes, indicating that the vvt is operating correctly. If they look the same then there's obviously a problem.

b) Assuming you have these two different graphs, you can overlay them and the crossover point gives the correct rpm to operate the vvt switch. It was suprisingly high with my setup, something like 5000prm. Mine being a 'k' though we're not comparing like with like here obviously.

I agree with James re: the AFR gauge, you really do need to know what's happening to fueling, certainly during the setup phase but I ended up leaving mine in as a permament fixture. I just feel that it gives an early warning if something goes wrong with the fueling for whatever reason, and allows you to tweek out those annoying little hiccups/flatspots that you invariably seem to end up with.

Looking promising though, 180bhp isn't too shabby for what is probably just a 'rough tune' at this stage.

Geoff.

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Ninehigh

posted on 7/8/10 at 12:23 PM Reply With Quote
After seeing 210 down the pub I was gonna guess 700 in my dreams






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